1. Technical Field
One aspect of the present invention generally relates to a vehicle mounting and alignment bracket for use in a radar application.
2. Background Art
Active safety systems for vehicles have been quickly growing in popularity in recent years. These systems typically sense a vehicle's external environment, determine a safety criticality level of current and near future events based on the sensed data, and actuate on-board vehicle systems to react accordingly. According to several proposals, the vehicle's external environment is sensed using a forward looking radar (FLR) unit.
Due to radar power limitations set by the Federal Communications Commission (FCC) and other international governing bodies, a radar is limited to a maximum threshold energy level. Given these limitations, the beam emitted from the FLR unit must be tight and narrow to maximize the range of the beam so that the FLR unit can sense at adequate distances from the vehicle. Therefore, the FLR unit, and hence the radar beam, is typically aligned with a relatively high degree of angular accuracy, such as vertical angular accuracy.
Mounting the FLR unit to a vehicle within the tolerable vertical angular accuracy limits can be challenging because vehicle mounting surfaces used to mount the FLR unit have relatively uncontrolled vertical angular accuracy. For example, the FLR unit can be mounted to the front surface of the vehicle front bumper. During vehicle assembly, the vehicle front bumper is attached to the end of the apron assembly through holes in the apron end and screws connected to the vehicle front bumper. The hole locations can vary significantly between apron ends, for example +/−3.0 millimeters, which may produce a significant variation in the vertical angular alignment of the front bumper mounting surface. If the FLR unit is mounted to this surface, then the use of expensive equipment and time consuming manual adjustment is often necessary to properly vertically align the front face of the FLR unit so that it can be used in active safety systems.
Manual adjustment has many problems. One of the problems is an ergonomics issue. The FLR unit is often located behind a removable fascia panel to minimize styling impact. The FLR unit is adjusted after the fascia panel is installed, thereby making it difficult to manually inspect the FLR unit, and even more difficult to make adjustments to the angular accuracy. These difficulties often translate into “blind” adjustments with poor ergonomic repeatability.
The alignment can be performed at a user-friendly “pit” station with an operator lowered to an appropriate height so that the operator has a clear view of the unit and relatively easy access to the unit. However, this is a relatively costly solution as the typical existing manufacturing facility pits were designed to allow access to the vehicle underside and are typically not long enough to allow access to the area at the front of the vehicle.
Moreover, the alignment process itself is relatively time consuming. One process requires the operator to hold an alignment gauge on the FLR unit, read computer feedback, and turn an adjustment screw in response to the computer feedback. This process requires a high level of attention from the operator until the adjustment is completed, preventing the operator from performing other assembly tasks during alignment.